Aims and Objectives

What is biological control of weeds?

Biological weed control is the deliberate use of endemic or introduced organisms (primarily phytophagous arthropods, nematodes and plant pathogens) for the regulation of target weed populations.

It aims to reduce weed density to economic and ecologically acceptable levels.

This goal is achieved by:
  1. Genecological studies of target weed populations;
  2. The investigation of potential control organisms associated with target weed species;
  3. Genecological and life history studies of potential control organisms, including virulence tests of pathogens (injury type and level produced per unit of pathogen) and efficacy of arthropods, together with detailed screening of their host range;
  4. Development of application strategies such as augmentation of endemic organisms, the release of introduced control agents and the use of plant pathogens as biocides.
Areas not covered

The terms 'natural' or biological control are often taken to mean all non-chemical means of pest control. In weed control they have been used for displacement planting, grazing management, crop rotation, breeding for genetic resistance, allelopathy, natural plant products as herbicides etc. Although these areas of research are not the subject of the group's activities, co-operation with workers in these fields will be necessary to integrate our activities into other pest control measures: we have made some progress in this direction, for example the joint session on biocontrol, physical control and allelopathy in the 2002 EWRS symposium.

Objectives of the working group

The working group was formed in 1984 and its main activity since then has been to hold biennial workshops lasting about two days on the biological control of weeds. These have been informal and convivial occasions which have given workers in this field, who are scattered throughout Europe a chance to meet and exchange ideas and information. The working group has also hosted sessions in the last two EWRS Symposia.